1. Field of the Invention
The present invention relates to floor structures of slope on indoor artificial skiing grounds.
2. Description of the Related Arts
Recently, some indoor artificial skiing grounds have been built for people to enjoy winter sports in all seasons. For the indoor artificial skiing grounds, artificial snow is produced by a snow machine, and heaped on the indoor floor.
FIG. 5 is a sectional view showing an example of the conventional floor structure of indoor artificial skiing ground. As shown in FIG. 5, the floor comprises a concrete base plate 1, a waterproof layer 8, a crushed stone layer 9, permeable asphalt 10, and artificial lawn 11. The concrete base plate 1 is constructed on foundations. The crushed stone layer 9 is spread over the base plate 1 with the waterproof layer 8 interposed between them. The artificial lawn 11 is spread over the crushed stone layer 9 with the permeable asphalt 10 interposed between them. Reference numeral 6 denotes artificial snow heaped on the surface of the floor.
FIG. 6 is a sectional view showing another example of the conventional floor structure of indoor artificial skiing ground. As shown in FIG. 6, the floor comprises a concrete base plate 1, cooling pipes 12, a waterproof layer 8, and artificial lawn 11. The concrete base plate is constructed on foundations. The cooling pipes are embedded in the base plate at specified intervals, in which a cooling fluid flows. The artificial lawn 11 is spread over the base plate 1 with the waterproof layer 8 interposed between them. Reference numeral 6 denotes artificial snow heaped on the surface of the floor. For the floor shown in FIG. 5, heat insulation is not taken into consideration at all. When the snow heaped on the floor melts in large quantities, much artificial snow must be supplied to keep the slope in a good condition. The supply of large amounts of snow increases the snow making cost, making the indoor artificial skiing ground uneconomical.
The floor shown in FIG. 6 is always cooled by the cooling pipes 12 embedded in the concrete base plate 1. Therefore, the artificial snow 6 heaped on the floor will not melt, remaining forever. As a result, the snow is gradually made dirty by the skiing of skiers. In addition, the snow is melted by the frictional heat generated by the skiing of skiers, and is frozen immediately after being melted. This repetition of melting and freezing makes the snow particles coarse, which gradually changes the snow into ice. The slope is changed into "Eisbahn" (a frozen ski slope). As described above, the conventional floor structure for the indoor artificial skiing ground has some disadvantages: the heaped snow becomes dirty, and the snow is changed into a frozen condition, so that such a floor structure cannot provide continually powder-shaped snow of good quality for skiers.